(1) Field of the Invention
The disclosure relates a touch panel and a contact information determining method of a touch panel.
(2) Description of the Related Art
Various display devices such as, for example, a liquid crystal display, an organic light emitting device, an electrophoretic display, a portable transmission device, or other information processing device may receive information by using various input devices. Recently, a touch panel has been widely used as the input device.
The touch panel may obtain contact information such as an occurrence of a contact event, a contact position, and a contact pressure applied to the touch panel when a physical object such as, for example, a finger or a touch pen (or stylus) contacts a touch screen. A desired command may be generated to operate a machine such as, for example, a computer, by touching the touch panel attached to the display device. Specifically, the desired command may be generated by writing characters, drawing symbols or clicking an icon on the touch panel using the physical object including the finger or the touch pen (or stylus).
A method of obtaining the contact information through the touch panel may include a resistive type, a capacitive type, an electro-magnetic (“EM”) type, an optical type, or a pressure sensing type according to a touch sensing method of the touch panel.
Among the above methods, the pressure sensing type touch panel, which senses a pressure applied thereto by an external contact, may use a piezoelectric effect. The method using the piezoelectric effect uses a phenomenon in which an electrical resistance of a material is changed in response to a pressure applied thereto.